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TitleLiDAR-based quantitative assessment of drumlin to mega-scale glacial lineation continuums and flow of the paleo Seneca-Cayuga paleo-ice stream
AuthorSookhan, S; Eyles, N; Bukhari, S; Paulen, R CORCID logo
SourceGAC®-MAC 2021, London, Canada: Exploring Geosciences Through Time and Space/GAC®-MAC 2021, London, Canada : Explorer les géosciences à travers le temps et l'espace; Geological Association of Canada-Mineralogical Association of Canada, Joint Annual Meeting, Abstracts Volume vol. 44, 2021 p. 289 Open Access logo Open Access
Alt SeriesNatural Resources Canada, Contribution Series 20210298
PublisherGeological Association of Canada
MeetingGeological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2021; London, ON; CA; November 1-5, 2021
Mediaon-line; digital
File formatpdf
AreaLake Ontario; New York State; Finger Lakes; Oneida Lake; Mohawk River; Great Lakes; Canada; United States of America
Lat/Long WENS -78.0000 -75.2500 43.8667 41.0000
Subjectssurficial geology/geomorphology; geophysics; Nature and Environment; Science and Technology; glacial landforms; drumlins; glacial features; proglacial lakes; glacial deposits; tills; clasts; glacial history; Wisconsinian glacial stage; deglaciation; ice flow; basin evolution; statistical analyses; erosion; bedrock topography; petrographic analyses; quartzites; modelling; Laurentide Ice Sheet; Seneca-Cayuga Ice Stream; Rochester Basin; Onondaga Escarpment; Valley Heads Moraine; Grimsby Formation; Allegheny Plateau; Digital elevation data; ice streams; ice-flow directions; machine learning; Artificial intelligence; Methodology; Phanerozoic; Cenozoic; Quaternary
ProgramGEM2: Geo-mapping for Energy and Minerals Hudson/Ungava, Northeastern Quebec-Labrador, surficial geology
ProgramGEM-GeoNorth: Geo-mapping for Energy and Minerals GEM Program Coordination
Released2021 11 01
AbstractShortly after 14,500 ybp during the deglaciation of the Laurentide Ice Sheet in eastern North America, the 80 km wide Seneca-Cayuga paleo ice stream occupied the overdeepened New York State Finger Lake basins. This presentation describes a new methodological framework for evaluating the topography of the former ice stream bed from high-resolution LiDAR DEM data, allowing mapping and analysis of almost four thousand subglacially streamlined bedforms such as drumlins and mega-scale glacial lineations. Qualitative and quantitative techniques were applied to the statistical analysis of bedform elongation ratio and orientation using Natural Neighbour Interpolation and unsupervised machine learning-based data clustering. Analysis reveals a geomorphic continuum of as many as seven morphotypes of streamlined bedforms from drumlins to mega-scale glacial lineations with intermediate 'channeled drumlins' possibly recording erosion of parent drumlins. Spatial analysis using orientation Grouping Analysis identifies several flow-parallel sets of bedforms reflecting the presence of multiple ice flow units in the ice stream up to 10 km wide that were topographically controlled by glacially-overdeepened basins of lakes Canandaigua, Seneca, and Cayuga (-151, -306, -242 below mean sea level respectively). Longitudinal variation in bedform elongation along as much as 60 km length of flow lines is provisionally interpreted as a proxy for ice flow velocities which ranged from steady state flow (drumlins), intermediate velocities (channeled drumlins) to fast flow (mega-scale glacial lineations). Quantitative data also identifies faster axial flow and slower flow along the margins of each ice flow unit. Fast flow was triggered at the grounding lines of flow units terminating in deep (as much as 600 m) proglacial lakes at the southern end of each overdeepened Finger Lake basin and propagated northwards along each flow unit at different rates reflecting the size and depth of frontal waterbodies. Petrographic data from tills derived from distinctive Paleozoic quartzites outcropping in a narrow west-east belt perpendicular to flow of each ice stream identifies extended longitudinal subglacial advection during fast flow consistent with very rapid bedform evolution.
Summary(Plain Language Summary, not published)
This conference presentation is based upon a recently published paper by the authors, on the ice streams of the Finger Lakes area, New York. The key message here is the application and interpolation of high-resolution LiDAR data to gain further insight into the morphology of the glacial landforms, and how they were formed.

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